The present invention relates to a fire retardant resin molded product, and to a process for preparing the same.
From a viewpoint of safety in an atomic power station, a demand for improvement of the reliability on and the health of electric cable for light-water type power reactor is now going on increasing. Saturated hydrocarbon polymers such as polyethylene and ethylene-propylene copolymer have been used as an insulating material for electric cable. These materials are widely used because of being relatively excellent in radiation resistance in addition of insulation ability, workability and economy. However, their mortal defect lies in combustibility.
Today a combustible resin such as polyethylene, polypropylene and ethylene-propylene rubber is mixed with various fire retardant additives for the purpose of making the resin fire retardant. As a fire retardant additive, a halogenated aliphatic compound such as chlorinated paraffine and chlorinated polyethylene and a halogenated aromatic compound such as hexabromo benzene and decabromo diphenylether are known. However, the halogenated aromatic compound, from the molecular structural point of view, is wanting in compatibility with resins and often blooms to the surface of resin during use for a long term and volatilizes at elevated temperatures and thereby has a tendency to bring on a change in fire retardance of resin.
Further, recently, in an electric wire, cable and various machinery and tools used for a nuclear reactor, breeder reactor and ionizing radiation generator, from the viewpoint of safety, it has become indispensable to be fire retardant. Therefore, various resin compositions used as insulating materials for electric wires and cables, packings and sealing materials, are required to be not only fire retardant but also radiation resistant.